Under the thin skin of narcissus: Facial muscle activity reveals amplified emotional responses to negative social evaluation in individuals with grandiose narcissistic traits

Individuals with grandiose narcissism exhibit enhanced antagonism and a defensive pattern of discordance between their emotional and physiological reactions to self‐threatening evaluations. Although theoretical perspectives link narcissistic defensiveness to negative emotions, empirical evidence linking grandiose narcissism to emotional reactivity remains mixed. The current study used self‐reported affect, electrocardiography, and facial electromyography (fEMG) to examine whether people scoring high in grandiose narcissism show amplified physiological and self‐reported emotional reactivity to negative social evaluation. Following two challenging cognitive tasks, participants received negative and neutral feedback in a face‐to‐face evaluation situation. Receiving negative feedback decreased self‐reported positive affect and dominance, slowed heart rate, and amplified fEMG activity related to frowning and eye constriction. Although self‐reported emotional reactions were unrelated to grandiose narcissism, fEMG activity associated with negative affect was significantly enhanced by grandiose narcissism. In conclusion, individuals with higher levels of grandiose narcissism may not be willing to report overt emotional reactivity to self‐threatening feedback, but physiological responses “beneath their thin skin” reveal amplified threat‐related facial muscle activity suggestive of a negative emotional state. Although grandiose narcissism is often linked with strong negative emotional reactions to social evaluations, direct evidence of the reactions remains mixed. We show that while narcissistic recipients do not report stronger negative emotions when receiving feedback on their performance than others do, their facial muscle responses to negative feedback are amplified. The findings align with theoretical accounts on narcissistic defensiveness and demonstrate a discordance in narcissistic individuals' self‐reported and physiological reactions to social evaluation.